Aberrant P-cadherin expression is associated to aggressive feline mammary carcinomas.

BACKGROUND: Cadherins are calcium-dependent cell-to-cell adhesion glycoproteins playing a critical role in the formation and maintenance of normal tissue architecture. In normal mammary gland, E-cadherin is expressed by luminal epithelial cells, while P-cadherin is restricted to myoepithelial cells. Changes in the expression of classical E- and P-cadherins have been observed in mammary lesions and related to mammary carcinogenesis. P-cadherin and E-cadherin expressions were studied in a series of feline normal mammary glands, hyperplastic/dysplastic lesions, benign and malignant tumours by immunohistochemistry and double-label immunofluorescence. RESULTS: In normal tissue and in the majority of hyperplastic/dysplastic lesions and benign tumours, P-cadherin was restricted to myoepithelial cells, while 80% of the malignant tumours expressed P-cadherin in luminal epithelial cells. P-cadherin expression was significantly related to high histological grade of carcinomas (p <0.0001), tumour necrosis (p = 0.001), infiltrative growth (p = 0.0051), and presence of neoplastic emboli (p = 0.0401). Moreover, P-cadherin positive carcinomas had an eightfold likelihood of developing neoplastic emboli than negative tumours. Cadherins expression profile in high grade and in infiltrative tumours was similar, the majority expressing P-cadherin, regardless of E-cadherin expression status. The two cadherins were found to be co-expressed in carcinomas with aberrant P-cadherin expression and preserved E-cadherin. CONCLUSIONS: The results demonstrate a relationship between P-cadherin expression and aggressive biological behaviour of feline mammary carcinomas, suggesting that P-cadherin may be considered an indicator of poor prognosis in this animal species. Moreover, it indicates that, in queens, the aberrant expression of P-cadherin is a better marker of mammary carcinomas aggressive behaviour than the reduction of E-cadherin expression. Further investigation with follow-up studies in feline species should be conducted in order to evaluate the prognostic value of P-cadherin expression in E-cadherin positive carcinomas.

Coordinated expression of galectin-3 and galectin-3-binding sites in malignant mammary tumors: implications for tumor metastasis.

Galectin-3 is a glycan-binding protein that mediates cell-cell and/or cell-extracellular matrix (ECM) interactions. Although galectin-3 is implicated in the progression of various types of cancers, the mechanisms by which galectin-3 enhances metastasis remain unclear. In order to elucidate the role of galectin-3 in the complex multistage process of cancer metastasis, we examined galectin-3 and galectin-3-binding site expression in a series of 82 spontaneous canine mammary tumors (CMT) and two CMT cell lines. Benign CMT tumors exhibited strong nuclear/cytoplasmic galectin-3 immunostaining, whereas malignant CMT tumors and metastases exhibited dramatically decreased galectin-3 expression with the majority of the immunostaining confined to the cytoplasm. Interestingly, intravascular tumor cells overexpressed galectin-3 regardless of their location. CMT-U27 xenografts displayed the same pattern of galectin-3 expression found in spontaneous malignant CMT. In parallel with the downregulation of galectin-3, malignant CMT displayed an overall loss of galectin-3-binding sites in the ECM and focal expression of galectin-3-binding sites mainly detected in intravascular tumor cells and endothelium. Furthermore, loss of galectin-3-binding sites was correlated with the downregulation of GLT25D1, a ß (1-O) galactosyltransferase that modifies collagen, and upregulation of stromal galectin-1. Finally, GLT25D1 mRNA expression was strikingly downregulated in malignant CMT-U27 compared with the benign cell line, and its expression was further decreased in a galectin-3 knockdown CMT-U27 cell line. We therefore hypothesized that the loss of galectin-3-binding sites in the ECM in conjunction with the overexpression of galectin-3 in specific tumor cell subpopulations are crucial events for the development of mammary tumor metastases.

Feline oral cavity lesions diagnosed by histopathology: a 6-year retrospective study in Portugal.

OBJECTIVES: The aim of this study was to analyse the frequency of oral cavity lesions in cats, their anatomical location and histological diagnosis, and the effect of life stage, breed and sex on different diagnoses. METHODS: For this purpose, a retrospective study comprising 297 feline oral cavity lesions was performed over a 6-year period between 2010 and 2015. Histopathological records from the DNAtech Pathology Laboratory (Lisbon, Portugal) were analysed. RESULTS: The incidence of oral disease was higher in male cats (n = 173; 58.4%), mature adults (ranging from 7 to 10 years old [n = 88; 33.0%]) and in the European Shorthair breed (n = 206; 73.6%). The gingiva was the site where oral lesions were most commonly found, with 128 samples (43.1%). Incisional biopsies were used to obtain the majority of samples (n = 256; 86.2%), while excisional biopsies and punch biopsies were performed in 36 (12.1%) and five (1.7%) cases, respectively. Inflammatory and neoplastic lesions accounted for 187 (63%) and 110 (37%) of the studied cases, respectively. Malignancies were found in >80% of neoplastic cases. Feline chronic gingivostomatitis was the most common histological diagnosis (n = 116; 39.1%), followed by squamous cell carcinoma (n = 49; 16.5%) and eosinophilic granuloma complex (n = 33; 11.1%). CONCLUSIONS AND RELEVANCE: The present work, involving a large series of samples of feline oral cavity lesions, from numerous geographically scattered practices and all examined at a reference veterinary pathology laboratory, adds important new understanding of the epidemiology of feline oral disease.

From bladder to systemic syndrome: concept and treatment evolution of interstitial cystitis.

Interstitial cystitis, presently known as bladder pain syndrome, has been recognized for over a century but is still far from being understood. Its etiology is unknown and the syndrome probably harbors different diseases. Autoimmune dysfunction, urothelial leakage, infection, central and peripheral nervous system dysfunction, genetic disease, childhood trauma/abuse, and subsequent stress response system dysregulation might be implicated. Management is slowly evolving from a solo act by the end-organ specialist to a team approach based on new typing and phenotyping of the disease. However, oral and invasive treatments are still largely aimed at the bladder and are based on currently proposed pathophysiologic mechanisms. Future research will better define the disease, permitting individualization of treatment.

Sialylation regulates galectin-3/ligand interplay during mammary tumour progression--a case of targeted uncloaking.

Galectin-3 is involved both in facilitating detachment of cells from primary tumour sites and favouring cancer cell adhesion and survival to anoikis in the blood stream. The mechanisms behind these apparently contradictory roles of the lectin have not yet been resolved. In order to investigate possible interplays between galectin-3 and its ligands underlying their role in the metastatic process, we examined mucin-1 (MUC1) and epidermal growth factor receptor (EGFR), well-known galectin-3 ligands, as well as galectin-3-binding site expression in a series of spontaneous canine malignant mammary tumours (CMMT) and a metastatic CMMT cell line. Despite the fact that CMMT cells expressed MUC1 and EGFR homogeneously over their plasma membrane, intravascular tumour cells, positive for galectin-3, expressed MUC1 and EGFR in a more focal membrane localization. Moreover, MUC1 overexpression in primary CMMT was present in parallel with down-regulation of galectin-3. Furthermore, in the CMT-U27 cell line, galectin-3 knock-down led to increased MUC1 expression, while MUC1 knock-down led to down-regulation of the lectin. Finally, removal of sialic acid from both CMMT and CMT-U27 xenograft samples exposed galectin-3-ligands throughout the tumour tissue, whereas these ligands were only present in galectin-3-positive invading cells in untreated samples. Interestingly indeed, we show that in vessel-invading cells, there is interaction between galectin-3 and the T antigen in vivo. We therefore hypothesized that loss of galectin-3 and sialylation-related masking of its ligands, in conjunction with their overexpression in specific tumour cell subpopulations, are crucial in regulating adhesive/de-adhesive events in the progression and invasive capacity of metastatic cells.